Hearing aid



' A ril 14, 1959 R. E. ERICK QN 2,882,348

HEARING AID Filed July 26, 1957 3 Sheets-Sheet 1 INV-ENTOR. Fa GER Z'Z [Rm/(s04 April 14, 1959 R. E. ERICKSON HEARING AID Filed July 26, 1957 3 Sheets-Sheet 2 April 14, 1959 R. E. ERICKSON 2,882,348

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FILE! 5 United States Patent HEARING AID Roger E. Erickson, St. Paul, Minn.,. assignor to Telex, Inc., St. Paul, Minn., a corporation of Minnesota Application- July 26, 1957 ,-Se1 lal' No; 674,343 4 Claims. (.Cl. 179-107 This invention relates to an improved salt-contained battery powered hearing aid which. may be worn. direct- 15! adjacent and: attached: to the ear of thewearer, either with' or withoutattachment to the bowof a standard spectacle; The invention relatesparticularly to a subminiature' type of battery powered; transistor hearing. aid, entirely self contained, containing. microphone and sound reproducer in mechanical arrangement so asv to minimize microphonic feedback, and toprovide adequate amplification of the sound frequencies normallyheard by human individuals. It is an object ofthe present in-' vention to provide a hearing aid of the aforesaidchar-ac ter and more particularly to-prov-ide a=hearingaid capable: of being; fitted to the wearer withoutundue indi? vidual attention;

It is another object of the invention to provide: any im.'- proved hearingaid of a: shape, weight, and so const-ructed so that it can be: worn comfort-ably by most individuals: It. is another object of the invention to'provide an im-' proved hearing aid capable ofibeing adapted. readily for attachment: to the earpiece bow of an: ordinaryspectacle, without any more" adaptation than to snip ofi the spec-- tacle bow at an appropriate length and attach. it to. the: hearing aid component by adhesive or the like.

It is another object ofi the. invention to provide an. imv proved hearing aid whereinthe battery is. so contained astobe capable. of being made available for easyaccessfor. replacement and yet somountedthat thebattery cannot. be readily: dislodged and st,. thereby prov-id ing' a structure which may be utilized easily by the elderly,, and bythose whose manual dexterity may be: im paired; It: is another object oi the invention toprov'ide an improved hearing aid which. is/frce from interference due to fluorescent lights and the like: electrical. dis-=- tu'rbance's'; It is. a: further objec't'of the invention to provide an improved hearing: a'idof the design such that it can easily be made ineitherright or leftso as to enable the' heater to mount the hearing aid adjacent either ear which may be impaired or: to provide hearing aids for" both: ears, andthereby accomplish biaural sound repro' d'u'ctio'n for the wearer.

Qther and further objects: are those inherent: in. the invention herein illustrated; described and? claimed and will be apparent as the description proceeds.

T0 the accomplishment of the" foregoing and relatedends, this invention then comprises the features hereina'ft'er' fully described and particularly pointedout in the: claims, the following description setting forth. in. detail certain illustrative: embodiments of: the inIvention these being indicative, however, of but a few of the various ways in' which the principles of the ihventi'o'n maybe employed.

The: invention is. illustrated withreference-to the drawings wherein Figure 1': is aside elevational view of a human individual shead showing one form of hearing aid apparatus 2-. of the present invention mounted in position. on the. ear. of the wearer.

Figure 2' is a side elevational view of. the human'head showi'nganother form of hearing aid apparatus of the present invention in place on the ear of the wearer and.- at'taclied to a spectacle bow..

Figure 3 is aside elevational view ofthe hearing aid apparatus shown in Figure 2 but removed from the ear ofthewearer.

Figure 4 is a rear elevational view of the: hearing. aid apparatus shown in Figures 1 and 2 taken in the direc tion of arrows 44 of Figure 3.

Figure 5 is a bottom view of'the hearing, aid apparatus.- illustrated' in Figure 3 taken in the direction of arrows 55 of Figure. 3.

Figure 6 is a partial verticalsectional view taken along the lines and in the direction of arrows 66- of Figure. 4.. In this figure the hearing: aid is-viewcd: from that side which is normally adjacent the. headof the wearer and the cover plate on this side; is removed in Figure 6. The sound tube. horn, throughwhichthe sound is delivered to the ear of the wearer, is showninsectionin Figure 6.

Figure? is a sectional view vertically (longitudinally) through the hearing. aid. apparatus, the sectioning being at a position and in the direction of arrows. 7.--7. ofv Figure 4'. In this view the soundtube horn of thehear. ingaid apparatus, which delivers the-sound-to the-wearer has been removed.

Figure 8 is a rear elevational View partly broken away takenjust inside the rear wall along the line and inthe direction of arrows 88 of- Figure 3. Again, the sound. tubehorn which delivers sound to the ear of the wearer: is removed from the hearing aidv case in this. view. The line of: sectioning along which Figure 8 is taken is-vshow nin. Figure 3.

Figure 9 is a bottom view, looking directly upward? ly, illustrating. the hearing aid case when it is in normal wearing; position as shown in Figures 1- and 2. For. simplicity, the horn 12 is not shown in Figure 9; Alsor in. this figure the battery frame is swung out and. isslightly deflected in one direction and the battery is cooked in the other. direction, preparatory to removal of the. battery.

Figure 10 is a separated sectional view' of the microphone metal sheath, withthe microphone w-ithin iti. The microphone is not shown in section; In this=view these components are shown removed from the case: of? the; hearing: aid. This view is taken in. the directi'oni ofarrows 10.10 and at the position of line 1010in: Fig-= ure 7. The hearing aid case and other components are,

for simplicity, not shown in Figure 10.

Throughout the drawing the same numerals refer to correspondingparts' of the apparatus.

Referring to Figure 1 there isillustrated" a" hearing aid generally designated 10 shown attachedto-the ear ofthe" human wearer. This hearing aidincludes abody portiorr and a. detachable horn" I-Z'WhiCh is attached at its small end to" a clear' flexible plastic tube 13 that in turn is attachedto a plastic ear-mold 14 that is individually fittedto the wearer; The horn 12 istapered and is press=fitted t'o' tubular bars' 2.9- on case 11', see'Figures 6 and7u The horn 1 2 is composed of a plastic material such as ol ethylene plastic and has a' moderate amount of flexibili'ty, a good smooth .feel and due' to such flexibility is easily attached by frictional engagement to the harder plastic case, as shown particularly in Figures 6 and 7 to which reference will be made. The born 12 has a tapered hole 62 through it for conducting the sound and the exterior of thehorn also tapers out to end 64,- whereprovision is" made for receiving end 64.

In Figure 1 the hearing aid is shown attached to the left ear of the wearer. but it will be understood that the apparatus may be made in either a right" or left form and used for either ear of the weare The hearing aid is entirely self-contained and needs no exterior battery supply or microphone. The horn 12 may be made in the form shown in Figure l, in which no provision is made to attach it to a cut-ofl? end of a spectacle bow, or it may be provided with a boss 12A having hole 12B in it for fitting to the bow B of a spectacle as in Figures 2 and 6.

Thus in Figure 2 the hearing aid 10 and body portion 11 are identical to those shown in Figure 1 but the horn 12 has a protuberance 12A which is cast integral with the horn 12. This protuberance is apertured at 12B for a moderate depth, so as to receive the stifiem'ng wire W which is normally used in the bow B of the spectacle S, as shown in Figure 2. The only necessity for fitting the horn 12 to a pair of spectacles is to snip off the spectacle bow, and strip back the plastic portion. The protuding wire W of the bow is then pushed into the aperture 123. Any suitable adhesive is used to then cement the wire reinforcement W into the aperture 12B and the horn 12 is accordingly attached to the spectacle bow B andis carried therewith. This in effect makes the hearing aid 10 a part of the spectacle, by mere attachment thereto, added stability of wearing is thereby provided. However it should be with sufficient stability as shown in Figure 1 because the born 12 encircles the top of the ear and the hearing aid body 11 fits as a suspended unit closely behind the ear of the wearer. The small plastic tube 13 comes down in front of thecar and curls into and is attached to the earmold 14. While the tube 13 has some degree of flexibility and the born 12 has a slight degree of flexibility, particularly towards its small end where it is attached to the tube 13, nevertheless the earmold attachment and the entire configuration of the unit serves to hold the unit with remarkable and entirely sufi'icient attachment to the ear of the wearer as shown in Figure 1, even where no attachment is made to a spectacle bow. Some users prefer the form of attachment shown in Figure 2 where the horn 12 is attached to the bow of the spectacle but this is not required for complete stability of the unit or for wearer comfort.

The horn 12 may be made as a solid boss and the portion 12A may be left unbored, and the agent who fits the hearing aid will then drill out the protuberance 12A to fit the diameter of the reinforcing wire W in the spectacle bow B, if that type of spectacle is to be attached thereto, or where a spectacle of the type having a metallic bow is used the protuberance 12A may be drilled to lit the particular diameter size of the spectacle bow wire and the latter may then be cemented firmly in place.

Referring particularly to Figures 3 through 9 the case 11 is a plastic molding formed so as to provide an interior space 16 which is of maximum depth throughout the portion from the bottom wall 17 to the wall 18 which defines the surface against which the sound reproducer 19, encased in a very soft rubber or plastic receptacle 20 is adapted to be positioned as shown in Figures 6, 7 and 8. The shape of the interior space 16, as viewed in Figure 6, is defined by the rear wall 21, wall 22, which is the surface that is normally adjacent the ear of the wearer,

tubular nipple at 29 having an tubular nipple connects with a pocket of corresponding sizein the horn 12 and the horn has a push fit onto andv the plastic tube 13, slipfitted to the I the bottom wall 17, the.

and the interior corner 18. The upperportion of the plastic molding 11 is then provided with a a pocket of smaller width; at 28-28. Finally this smaller pocket terminates at a. axial hole 30therein... The,

understood that the hearing aid may be worn I I seats on the nipple 29 and against the surface 32 of the plastic case. Adhesive may be used to hold the born 12 attached to the case 11 at the nipple 22 and surface 32 if desired although normally the slight flexibility of the plastic of which the horn 12 is made is sulficient to provide a lasting gripping action sufiicient to hold both parts together.

The aperture 16 is provided with an interior boss 34 at one corner into which there is molded a metallic screw anchor 35. This boss 34 provides a surface 34A upon which a battery frame generally designed 36 is adapted to be mounted by means of the screw st-ud 37 which serves as a pivot about which. the frame 36 may be swung from the position shown in Figure 7 to the position shown in Figure 6. In the position shown in Figure 7 the frame 36 holds the battery 38 in electrical contact with appropriate contacts Within the hearing aid case 11 and hence provides the electrical supply for the hearing air apparatus. When the frame 36 is swung to the position of Figure 6 the battery 38 can be taken out by deflecting the frame 36 and case 11 a little, as shown in Figure 9, but battery 38 will not fall out of its own accord. It may be noted parenthetically that a single mercury type cell forms the battery 38 and this provides sufiicient power to energize the transistor amplifier circuits of this hearing aid apparatus.

The transistor amplifier is mounted upon a printed C11- cuit board 40 which is anchored in place by an enlarged head 37A on the same stud 37 which holds the battery frame 36 in place in the apparatus. The stud 37 is provided with a screw threaded aperture 37B at its outer end to which a screw 41 may be attached for holding one corner of the removable cover 42 in place on that side of the case 11 which normally contacts the head of the ear. Other corners of the case are held by screws 43-43 which are entered into the metallic brackets 44 and 45 at the lower end of the housing, these brackets being provided with screw fitted apertures at 44A and 45A. The brackets 44 and 45 also serve as electrical connectors to a rheostat and switch 46 having a disclike control knob 47. The brackets have a shape shown in Figure 8 and are riveted at 49 to the printed circuit board 40 and support the board 40 in the case 11.

Also there are a plurality of circuit components shown opposite the bracket 50, on the right side of the printed circuit board 40 as shown in Figure 8. These individual circuit components include the transistor, condensers, resistors, etc. making up the multiple stage transistor amplifier circuit of the hearing aid. In the hearing aid assembly when the circuit board 40 is held in place as illustrated, there is a space behind it as shown in Figure 6, and to the left of the element 40 as shown in Figure 8.

It is into this space, which is illustrated in Figure 7,

that the battery frame 36 swings and carries the battery 38 and thus brings the battery into position so as to form its electrical contact with the suitably disposed contact pieces on the hearing aid board 40 and elsewhere within the space 16. At the bottom of this space there is also the microphone apparatus 52 which is entirely ensheathed in magnetic material 53. The magnetic sheath 53 is made in the form of two pans which nest together as shown in Figure 10, and enclose the entire microphone except for openings as at 54 through which the electrical connections emerge from the microphone,

52. The sheath 53 is of highly permeable magnetic material but the sheath is quite thin and the sound waves,

which enter the case portion 11 through a small opening 55, see Figure 3, impinge against the adjacent fiat surface of the microphone case metal 53 and by vibrating such case serve to operate the microphone 52 which is entirely encased by the metal case 53. The effect of 7 this is that while the mechanical force of the sound waves are permitted to operate the microphone without substantially decreasing their effect in passing through the case 53, still at the same time any magnetic disturbance in the region of the microphone 52 is shielded away from the microphone by means of the magnetically permeable metal forming the case 53. This serves to reduce that kind of noise interference which has been found to be due to the proximity of the hearing aid to electrical apparatus such as fluorescent lights, etc.

Referring to Figures 6-9 particularly, it will be noted that the frame 36 which serves as a swinging mounting for the battery 38 has a maximum thickness at the wall portion 36A which is exposed to the rear of the hearing aid case 11 when the frame 36 is swung closed as shown in Figures 4 and 7. This wall portion 36A terminates as a small projection 36B at the corner opposite the pivot screw 11 and the user may accordingly insert a fingernail behind the portion 36B for swinging the frame 36 outwardly to the position shown in Figure 6. The frame portion 36A is of slightly narrower width at the corner and the small aperture 56 in the rear wall of the hearing aid case 11 is likewise somewhat narrowed at its upper portion 56A. The remainder of the frame 36 is considerably thinner and forms a ring 36D, which is displaced to the position shown in Figure 8. Accordingly, the battery, which has a larger diameter flange 38A at one face, may seat with one portion of the battery case positioned in the ring 36D and the flange 38A resting on the surface of the ring. When the frame 36 is swung to its outward limiting position as shown in Figure 6 a certain portion of the battery 38 is still situated within the opening 56 and the battery 38 will therefore not simply fall out of the frame 36. This is an advantage for some users of hearing aids, particularly older people, may swing the frame 36 to its open position, either through curiosity or a misbelief that the battery is not operating properly, or for other reasons and if the battery 38 is able simply to fall out of the frame 36 when the frame 36 is in an open position, the battery could be easily lost and since it is no larger than a moderate size button, the battery can easily fall and roll to some place where it is irretrievably lost by the user. According to the present invention this problem of lost batteries is obviated, at least in part by making the frame 36 so that, while it permits the removal of the battery by a conscious act, yet the battery does not simply fall out of the frame when the frame 36 is moved to its open position. Hence as shown in Figure 6 and in Figure 9 the battery is ready to be removed but in order to do so the frame 36 must be deflected in the direction of arrow 58 as shown in Figure 9. This is possible due to a slight looseness of fit of the pivot bearing 37 in respect to the frame 36 and also due to the fact that the case 11 and the frame 36 are made of slightly flexible plastic material and the frame 36 when moved to its open position and is then pushed sideways in the direction of arrow 58 will deflect the case 11 a little bit. This provides enough room so that, in the position shown in Figure 9, the battery 38 may be cocked to the position shown in that figure, where the edge 38E is just ready to clear the hole in the battery frame 36 and the battery can then be withdrawn in the direction of the arrow 59. This is not at all diflicult to do but it does require a conscious act of the user and in so doing the user is prevented from losing the battery through mere casual or inattentive opening of the battery frame 36.

Referring to Figures 6, 7 and 8, particularly, the sound reproducer or receiver 19 may be of the crystal or magnetic type and is enclosed in its usual case. Around the case, however, there is placed a very soft plastic sheath 20 which is in the form of a cup or collar, and is provided with an aperture 60 at one side, in alignment with the sound delivery tube 61 of the sound reproducer 19. Accordingly sound produced by receiver 19 can leave the tube 61 and proceed through the aperture 60 to the aperture 30 in the tubular connection 129 and thence enter the horn 12 and proceed through-the gradually tapered curved aperture 62 and be delivered at the connection end 64 where attachment of the horn is made to a plastic tube 13 as previously described. The sound is then conducted through the plastic tube '13 to an earmold 14 which is of a shape that fits the external portions of the ear canal of the user.

The very soft plastic or rubber sheath 20 entirely surrounds the sound reproducer 19 and is provided with a flange 66 by which-the back side of the sound'reproducer is separated from the adjacent portions of the case 11 and the end surface of the hearing aid circuit board 40. Accordingly the mechanical conduction of sound vibrations from the receiver 19 to the microphone 52 are minimized to an unobjectionabl degree. At the same time the sound waves delivered by the sound reproducer 19 are sealed by the flange end 67 of the sheath 20 and these are not permitted to travel around through the air within the case to the microphone 52. Accordingly the sound waves are delivered and conducted through a sealed mechanical channel which begins at the sound delivery tube 61 of the sound reproducer 19 and thence enters through the port 30 of the nipple 29 and through the channel 62 of the horn 12 and through the tube 13 to the earmold 14 and being thus delivered directly to a soft portion of the ear canal and in sealed relation to the walls of the canal, very little soundis accordingly transmitted through the open air back to the microphone 52 and the sound reproducer 19- are in close mechanical proximity but with objectionable feed-back either mechanically or through the air from the sound reproducer to the microphone.

As many widely apparently different embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that I do not limit myself to the specific embodiments herein.

What I claim is:

1. A hearing aid comprising a case of slightly flexible material, a complete sound pickup and amplifier system in said case including a microphone, an electrical sound amplifier, a battery for said sound amplifier, and a sound reproducer, said apparatus being characterized in that said case is provided with a battery holder of generally planar shape attached to the case for movement edgewise fro-m an operating position where the holder is within the case to a battery changing position where the holder is partially exposed outside of the case, said holder being shaped for receiving said battery therein when the battery is moved in a direction generally normal to the plane of said holder, said holder being shaped so that the battery when held therein is only partially exposed when the holder is moved with reference to the case to the battery changing position, said holder in said position and said case being defiectable relative to each other to a position such that the battery may be cocked to a position out of the plane of said holder and withdrawn from the holder and said case.

2. The hearing aid apparatus specified in claim 1 further characterized in that said battery holder is pivotally mounted on said case for swinging movement from its operating to its battery changing position.

3. The hearing aid apparatus of claim 1 further characterized in that said battery holder includes a small projecting section which overlaps the case when the battery holder is in its operating condition so as to enable the user thereof to insert an object behind said projecting section for operating said battery holder.

4. A hearing aid apparatus comprising a case of material such that magnetic waves may pass therethrough, said case including a complete electrical sound receiving and amplifying system including a microphone, a multiple stage electrical amplifier and a sound reproducer complete with power supply therefor, said apparatus being ReferencesCited in the file ofthisv patent UNITED, STATES PATENTS 1 Rohr July 4, 1950 Nicholides Sept. 20, 1955 De'Angelis May 28,1957. 8 FOREIGN PATENTS I I ltalv May 15, 1954 Great Britai Sept. 21, 1955: Great Britain 'Nov. 7, 195 6 GreatBritain. Nov. 14,1956 

